1. Field of the Invention
The embodiments described herein relate generally to tomographic systems, such as computed tomography (CT) systems, and, more particularly, to CT systems that scan a continuous stream of objects.
2. Description of the Related Art
At least some known tomographic systems scan a continuous stream of objects. In such tomographic systems, it is generally necessary to partition data generated by the tomographic system into blocks associated with each object in the stream of objects. For such tomographic systems to perform partitioning of the data successfully, the tomographic system determines an extent of each object and completes data acquisition for each object as each object passes through the tomographic system. As used herein, the term “extent of an object” refers to the physical boundaries, dimensions, and/or measurements of the object, such as the physical volume of the object, and/or data representing the physical object. In at least one known tomographic system, a machine control for a scanning device generally includes information about each object from an external system that transports the objects into a scanning device, such as a CT system. One such external system includes passive curtains to determine the extent of each object. However, objects passing through the passive curtains may be repositioned, such as “joining up” or shifting orientation, before and/or inside the scanning device. Such repositioning may cause confusion between the extent of an object as externally measured, and the extent of the object once inside the scanning device. As such, there is a need to determine extents of objects within the scanning device.
In at least some known tomographic systems for scanning a stream of objects, the reconstruction subsystem, which generates high resolution images, cannot keep pace with the data acquisition of the scanning device. Such tomographic systems rely on gaps between the objects within the stream to catch up to a flow of objects. More specifically, during the gaps, the tomographic system can process data of one object before data for the next object in the stream is acquired. As such, there is a need to collect data only during the physical extent of the objects and not during the intervening gaps.